Plasmas are comprised of a medium of charged particles, ions, and electrons and are one of the most common forms of matter in the universe. Although plasmas generally exist in stars and clouds in space, they can be created by heating or applying a strong electromagnetic field to a neutral gas. High heat or pressure can strip electrons from atoms, creating positively charged ions and free electrons in an electrically-conducting medium, such as a plasma.
Of current interest is the formation and behavior of plasmas created by hypersonic vehicles passing through the atmosphere. These vehicles leave behind a plasma trail which can interfere with electromagnetic signals due to the conducting nature of the material. This presents interesting challenges both for radar detection of these vehicles and for radio communication and guidance through the plasma layer.
This paper discusses the finite-difference, time-domain (FDTD) method to simulate the behavior of plasma materials using Remcom’s XFdtd® 3D Electromagnetic Simulation solver. The simulation of plasmas is discussed starting with an explanation of the frequency-dependent model used, followed by validation of the method in one and three dimensions. In three dimensions, both monostatic and bistatic radar cross section results will be presented for validation.